Designing and Application of 1000,000 TPY Cement Grinding Station
1000,000 TPY cement grinding station production line takes use clinker, slag individual grinding technology, and clinker grinding uses G120~50 Roller Mill and Φ3.2m×13m double circle extruding and grinding technology composed of cement mill, while slag grinding mill takes use Φ3.2m×13m mill which is fewer in our country to update the circle grinding system composed of high efficient separators. After months debugging and operation, this grinding station operation is stable gradually, reaching the goal of good quality, high efficiency and lower consumption.
Main equipment and processing of production line
1. Design of Clinker Grinding Production Line. After Gypsum, Clinker of Rotary Kiln, Limestone weighted by Belt Scale, then the mixture will be sent to flow weighting bin by Belt Conveyor and Elevator, during this process, material will get rid of magnetic metal by steel separator which will be fed to Roller Mill, extruded material will go through Material Cake Elevator to Dispersed Classifier, however the rough material larger than 2.5mm will go into stable current weighting bin which will be extruded together with mixture by Roller Mill, meanwhile the superfine material less than 2.5mm will go into mill for grinding. The material going out of mill will be conveyed together with weighted fly ash to end of kiln by mixture elevator by conveying chute, then go through conveying chute of separator to K type Inside Circle Separator, the rough material will return back to mill, superfine power will be conveyed by gas conveying chute to finished products elevator to reaching finished products warehouse. Gas going out from mill with dust will be treated by dust collector of kiln end, and then exhausted out through exhaust blower; meanwhile the superfine powder collected will go into mixture elevator.
2. Design of Slag Grinding Production Line. The mixture with Weighted Gypsum, Dry Slag, and Fly Ash by Belt Scale will go into grinding mill through elevator, during this process; material will get rid of magnetic metal by steel separator. Material out of mill will go into mixture elevator through conveying chute of kiln end, then they will be divided into 2 parts and conveyed into K type high efficient separator individually through conveying chute of separator, the separated rough powder return to mill, while cement finished products will be collected by air slideoulse type of dust collector, the superfine powder will be sent to finished product elevator through air conveying chute to reaching finished product warehouse. Gas with dust out of mill will go into as K type superfine high efficient separated powder as first wind swept into separator , while fresh air will be treated as 2nd, 3rd times powder wind swept into separator, then the gas with dust will be treated by Air slideoulse type of dust collector, then exhaust by exhaust blower.
3. Mixed design of Slag Superfine Powder and Clinker Powder. During individual grinding processing, clinker and superfine slag powder should be weighted exactly and mixed evenly; beside they should meet the fineness requirements. Thus we take use screw scale as metering equipment together with gas conveying chute which could be used not only as mixing equipment, but also conveying equipment. While screw scale composed of overflowing single tube screw scale and metering single tube screw scale, then first one make the current stable and ensure the even feeding; later one make sure exact and stable weighting. As gas conveying chute takes use particulate fluidization principle for material conveying, the slag powder and clinker powder will mix and roll during conveying process.
Operation Situation of System
1. The manufacturing and debugging of clinker double circle extrusion grinding system. As the requirements of extrusion grinding system is to take use LV large circle operation, during operation, the operation pressure of hydraulic system of roller mill is lower, the circling volume of material is enlarged which make the total volume of superfine powder during extruding mixed material will be added, ensure the implementation of output increasing of ball mill. Due to proper reduction of pressure, finish product percentage of material cake will be lower and the chance for over-grinding inside of mill will decrease, at the same time, lower pressure will make less abrasion of roller surface of roller mill and update the stability of equipment operation. In Extrusion Grinding System, due to the function of dispersed classifier, the material larger than 3mm will be circled between roller mill and dispersed classifier without any effect to ball mill, but through adjustment on operation specification of roller mill could make the finished product percentage of dispersed classifier achieves 50% hardly including powder larger than 3mm which ensure the high & stable output for the whole line.
As roller mill and dispersed classifier composed of closed circuit, material powder fed into ball mill will almost keep the same, while the average powder diameter of material for mill is 1.5mm, thus this basically replaced the function of rough bin of ball mill. Meanwhile not only average material powder diameter will be reduced a lot, but also the inside of powder has some micro-crack, which largely updates the grind-ability. In order to adapt the change of material powder, the crushing capacity of ball mill should be reduce and its grinding capacity should be updated, thus accordingly reduce the diameter of grinder and the length of first bin. Mill take use superfine and high efficient technology elite, so it is more advanced in technology, and newer on structure of grinding technology, and take use double screening partition device instead of original partition device, which will not be affected by material level of front and behind bins, own strong material flowing function and could control the rate between material and ball mill for each bin.
Take use circle circuit grinding system composed of high efficient separator and ball mill and concentrate pre-separating of separating, cage type separating of whirling separator, rotary separator of rotor separator, other ways dust separating and cleaning of rough powder, only need to adjust the rotating speed of main shaft of separator and open range of wind door of circle fan to control the fineness of finished product in a suitable scope.
2. Debugging and manufacturing of slag circle circuit grinding system. Locally takes use Φ3.2m×13m ball mill for slag grinding, according to our research, most factories take use open circuit for manufacturing, output of the equipment is lower in one hour which couldn’t achieve the goal of large scope. Using open-circuit for manufacturing, quality of finished products is hard to control, and over-grinding appeared inside of mill. According to the characters of slag, using closed-circuit for manufacturing, in one side it could reduce electricity consumption of grinding, in the other side it could reduce over-grinding. As the requirement of specific surface area rate is higher which should reaches over 400m/2kg and much higher than normal specific surface area rate, thus it should ensure the enough time for slag staying inside of mill, while there are three bins inside of mill, in order to update grinding efficiency of material, we should add 3%~5% fly ash during slag grinding.
Jiangsu Pengfei Group has the comprehensive ability to supply the best services of designing, manufacturing, installation and debugging for the complete cement equipments with daily capacity of under 8,000tons. Main products of Pengfei are: Rotary Kiln, Ball Mill, Cooler, Humidification Tower, Dust Collector, Dryer, Crusher, Vertical Mill and Compound Fertilizer Equipment.