The roller press combines the disadvantages of the double closed circuit grinding system
Date：2019-07-12 13:55 Source：未知Views:
After 2005, the new cement grinding production line is mainly the combination of roller press and double closed circuit grinding system.This was considered to be the most advanced grinding process of the time.Now we have a lot of shortcomings in analyzing this process.Optimization space has disadvantages, and there are no better advantages than optimization.Here we first talk about the rolling mill double closed circuit grinding process disadvantages:
1;The fine powder produced by the roller enters the tube mill for grinding:
we know that a certain amount of finished cement products meet the particle size requirements after each crushing or grinding process in the grinding process.20-40% of the finished product is produced after the roller press of the pre-grinding equipment is crushed.The combination of the roller press with the double closed grinding system does not allow the removal of these finished products.This qualified fine powder enters the tube mill and continues to grind to produce a severe overgrinding which affects the grinding performance of cement clinkers and other harder materials.(this disadvantage is also the rolling process of the roller mill, while the tube mill is the disadvantage of the open flow process.)
2: excessive motor power configuration:
the roller press is combined with the double closed-circuit grinding system. The roller press system is equipped with a set of air selection system, such as the 1712 roller press fan with 560kw cycle.The cycle of the two-stage tube mill also requires a classifier.The machine power is generally 700kW, and 700kW is only used for classification of classifiers.The motor power reaches 1500kw, which is more than 800kw compared with the two-in-one coil grinding process.It's a waste.
3: more equipment, more investment:
compared with the two-in-one cycle grinding process, v-type separator behind the increased cyclone collector and dust collector, increased equipment.
4. Combined grinding and powder separators with high power efficiency:
most existing grinding and separation machines are o-sepa.In practice, the sorting machine requires a high - power fan.Most of the units used are too small and therefore have a significant lack of sorting capacity, which limits production at stations.
5: the tube mill does not match the pre-grinding equipment:
the fineness of the material after roller pressure reaches 40-65% of the 80um sieve, and the flow rate will increase after the material enters the tube mill.Compared with the imbalance, the material surface is reduced, the abrasive body cannot work 100%, which shorens the time the material stays in the warehouse, and there are factors such as large gradation of the abrasive body, which reduces the overall grinding efficiency.
6: the tube mill is supported by sliding bearing, which needs to consume 10% of the motor power.
Therefore, the bearing capacity of 4213 cement grinding body is only 230t.Compared with the rolling bearing m, it got sick and installed the 30t grinding body, which reduced the grinding capacity.
7. The strength of cement clinker cannot be maximized:
the material entering the pipe mill is not uniform in thickness. Materials that are easy to ground, such as mixed materials, have been ground to small fineness and have been ground, resulting in increased water demand of finished cement products..Grinding materials such as cement clinker or slag is not easy.The size of slag does not meet the requirements.For example, cement clinker should be ground to 400 or more specific surface area, but only to 320 or so specific surface area.In the absence of grinding, a false specific surface area resulting from mixing of the mixture material occurs and does not maximize the strength of the cement product.Affects the quality and maximization of cement products.
8. High grinding power consumption:
as the grinding system cannot reach the optimal production level, the grinding power consumption is more than 37kw. H/t.High grinding power consumption.