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What is the difference between a dry ball mill and a wet ball mill in production?

2019-11-14 17:48:09 | burning
Product introduction :https://www.cementepc.net/grinding/Cement-ball-mill.html

Jiangsu LVSSN company core cement epc


Ball mill is a common equipment in grinding equipment, but also the material after the crushing and screening operation, the key equipment for grinding.According to the classification of grinding, the ball mill can be divided into dry ball mill and wet ball mill.What are the differences between a dry ball mill and a wet ball mill?



Dry ball mill



1. How it works




When the dry ball mill is running, the material enters the first bin of the mill uniformly through the feeding device through the feeding hollow shaft screw, and the bin is equipped with stepped lining board or corrugated lining board, which is equipped with steel balls of different specifications.The centrifugal force generated by the rotation of the ball mill barrel will bring the steel ball to a certain height and then it will fall down.

After the material is roughened in the first warehouse, it enters the second warehouse through the single layer compartment plate, which is equipped with flat lining plate and steel balls of different specifications to further grind the material.Finally, qualified materials are discharged through the discharge grates to complete the grinding operation.

The working principle of wet ball mill is similar to that of dry ball mill, but different.Wet ball mill needs to add appropriate amount of water or anhydrous ethanol in the grinding process, which means that the grinding concentration has certain requirements.The amount of water is determined by the nature of the material.Qualified materials are discharged out of the cylinder through the discharge part, and the unqualified materials are returned to the wet ball mill for further grinding.

 



2. Structural construction




Dry ball mill and wet ball mill both include feeding part, feeding part, rotating part, transmission part (reducer, small transmission gear, motor, electric control) and other major parts.

The difference is that the structure structure of the dry ball mill is relatively more complicated than the wet ball mill, and its discharge mouth is straight cylinder shape, and it is equipped with air device, dust pipe and dust collector, which is determined by its working principle.The structure of wet ball mill is simple, no need to add too many auxiliary accessories, discharge mouth is like a horn, built-in screw device to facilitate discharging.



Wet ball mill



3. Scope of application of ball mill




In general, the dry ball mill is suitable for all kinds of metal ore, non-metal ore, including water will react with materials, such as cement, marble and other building stone, or require powder form to store and sell products.In addition, if the plant is located in a dry area, water resources are scarce, for the sake of water conservation, can use dry ball mill.

Wet ball mill is applicable to a wide range of metal ore, non-metal ore, including gold ore, silver ore, copper ore, iron ore, molybdenum ore, phosphate ore, feldspar, fluorite and so on.Wet ball mills can be used as long as the material meets water and does not affect the quality of the final product.

It should be noted that when wet ball mill is used, the proportion of steel ball, material and water should be determined through ore dressing test to ensure the ideal grinding effect.As for the choice of what kind of grinding equipment, or depends on the ball mill follow-up operations, product nature and production costs.

Only by finding out the suitable grinding mode of the material, can the ball mill run efficiently and well, the two grinding equipment have their own advantages, we are still in the nature of the material, characteristics and the requirements of the product, working environment and other aspects of the rational choice.



The page source: https://www.cementepc.net/Industry/What-are-the-differences-between-a-dry-ball-mill-and-a-wet-ball-mill.html

How can ability judge ball mill load

2019-11-14 17:45:10 | mill
Product introduction :https://www.lvssn.com/mill/Cement-ball-mill.html

Jiangsu LVSSN company core cement epc


Ball mill load is the sum of ball load, material load and water amount in the mill.What are the methods of measuring ball mill load?
 



1. The sound method




Industrial production practice shows that the sound of the ball mill has a certain relationship with the material load. The essence of this method is to determine the material load in the ball mill according to the difference in the noise produced by the ball mill.When the material load in the ball mill increases, the noise intensity of the ball mill decreases.On the contrary, the noise intensity of the ball mill increases, that is, there is a relationship between the noise intensity of the ball mill and the material load in the ball mill.Therefore, the noise intensity of the ball mill can be used to evaluate the material load in the ball mill.




ball mill
 



2. Active power method




The working characteristics of a wet ball mill can be directly described by the useful power consumed.When the mill and its rotating speed are fixed, the theoretical calculation and actual test results show that there is a certain relationship between the active power of the ball mill motor and the load of the ball mill.With the increase of the ball mill load, the active power of the ball mill motor rises obviously at the beginning, and after reaching a certain extreme value, the active power decreases instead with the increase of the ball mill load. This extreme value can be considered as the optimal point of the ball mill load.Therefore, the useful power is directly related to the load of the ball mill.
 



3. The vibration method




When the ball mill is running, the grinding body and the material are on the side of the mill, and the grinding material and the rotating part of the mill are in a serious unbalance state, which causes the unbalance centrifugal force and makes the mill system vibrate.When the speed of the mill is unchanged, the vibration intensity of the mill is related to the amount of the grinded material.
 



4. Pressure sensor method




A load sensor is installed under the bearing of the feeding end and discharging end of the ball mill to continuously weigh the mill, so as to determine the total amount of ball medium, ore and water in the ball mill and determine the load of the mill.Its advantage is simple, the disadvantage is the detection accuracy is not high, can not accurately detect the ball mill medium, ore and water in the respective amount.In addition, the wear of ball mill lining plate, the change of ore property, the change of steel ball weight before and after adding will have a great impact on the test results.




ball mill
 



5. Differential electromagnetic sensor method




It only measures the useful part of the vibration signal of the mill shell and eliminates the general interference signal.The sensor can be mounted at a distance of 71 ~ 80mm from the shell of the ball mill.The sensor has high reliability and sensitivity and low signal transmission delay.But this kind of detection system can't detect the concrete value of the ball mill's medium filling rate, material ball ratio and grinding concentration.
 



6.Hall power transmitter method




In the closed circuit grinding system of a ball mill with a double screw classifier, the load of the ball mill is indirectly reflected by measuring the amount of sand returned by the classifier.In the grinding production process, when the load of the ball mill exceeds the normal value, the coarse particle composition of the ball mill will increase, which will definitely increase the amount of returned sand; otherwise, the amount of returned sand will decrease.Therefore, it is feasible to measure the load of the ball mill indirectly by measuring the amount of returned sand. The hall power transmitter is used to measure the electric power of the classifier.At the same time, the absolute value of power is not required to be measured in this measurement, so only the single-phase power variation value of the three-phase motor with internal rotation of the double helix classifier is measured, so as to reflect the relative change of the returned sand amount and realize the automatic control of the ball mill load.

The single factor detection method introduced above is unable to judge the medium filling rate, material ball ratio and grinding concentration of the ball mill, so it is more important to choose the appropriate method according to the actual situation of the site.




The page source: https://www.lvssn.com/company/What-are-the-methods-of-measuring-ball-mill-load.html