During the operation of the mill, the powder output rate is getting lower and lower, which seriously affects the benefits of the enterprise. How to solve these problems has been a headache for many enterprises. The editor has compiled some methods to improve the powder output rate and production efficiency of Raymond mills for the reference of decision-makers.

1. Reasonably select the rotational speed of the main machine and enhance its grinding force

Since the grinding force originates from the centrifugal force of the grinding roller, the speed of the main machine directly affects the magnitude of the grinding force. Low rotational speed of the driving shaft may be one of the reasons for the low powder yield. Insufficient power, loose or severely worn drive belts can all cause unstable rotational speed and deceleration of the driving shaft.
Suggestion: Considering the load-carrying capacity of the main motor is a factor in enhancing the production efficiency of the pendulum mill. Increase the kinetic energy of the mill's operation by adjusting the belt or replacing it with a new one.

2. Adjust the air pressure and air volume of the blower reasonably

Due to the significant differences in the physical properties and chemical compositions of non-metallic mineral raw materials, such as graphite and gypsum, which have lower densities, when adjusting the air pressure and air volume, they should be relatively smaller than those of denser minerals (such as barite and iron ore), and the adjustment should be appropriate.

• If they are too large, it is easy for coarse particles to not be well classified when passing through the classifier and mixed into the finished product, leading to unqualified products;
• If they are too small, material blockage is likely to occur inside the main unit, causing the machine to fail to operate normally.

3. Reasonable design of the scraper device and selection of wear-resistant materials for grinding rollers and grinding rings

The scraper device is an important device that directly lifts materials between the grinding roller and the grinding ring. Through technological development and improvement, the scrapers of Raymond mills are all designed quite reasonably, capable of lifting and allowing materials to be thoroughly ground between the grinding roller and the grinding ring.
Severe wear of the main grinding wear parts such as the scraper, grinding roller and grinding ring will affect the amount of powder output.

• Wear-resistant parts made of highly wear-resistant materials, such as high-chromium cast iron, should be selected.
• If the scraper cannot lift the material, or the grinding roller and grinding ring are severely worn (failing to perform a good grinding effect), it will result in a low powder processing rate. Worn parts should be replaced in a timely manner.

4. Do a good job in lubricating the equipment

Another possible reason affecting the rotational speed of the main machine of the grinding mill could be the dullness of the grinding teeth. Therefore, it is necessary to frequently inspect the transmission parts such as the grinding teeth and make preparations for lubrication and replacement.

5. Clear the pipes and ensure proper sealing

The blockage of the conveying air duct of the mill leads to the inability to transport the powder normally, which may cause low powder output or even no powder at all. To solve this problem, the machine needs to be shut down to clear the material in the pipeline and then restarted for discharging.

Suggestion 1 (Pipe and Silo Design)

The ultrafine powder contained in the material has a strong coagulation effect, and its loose specific gravity is small, occupying a large volume (the volume of 800 mesh products with the same weight ratio is nearly twice that of 325 mesh products). It is also prone to adhering to the pipe wall and silo wall and is not easy to fall off. Therefore:

• The inner wall of the pipe and silo should be as smooth as possible, with excellent inner lining of galvanized sheet or stainless steel sheet.
• The discharge taper of the silo should be as small as possible, and an outstanding tank wall vibrator should be equipped.

Suggestion 2 (Pipeline Sealing Inspection)

In addition to blockage, the sealing performance of pipelines also affects powder output. Poor sealing of pipelines can lead to an increase in dust, negative pressure imbalance, and a low powder conveying rate.

• The sealing of pipelines needs to be inspected thoroughly before production.
• If the powder lock device at the discharge port of the Raymond grinding production line is not adjusted to the correct state, it will result in poor sealing and powder backflow. Therefore, ensure that the powder lock device, the return air pipe valve and other valves on the pipeline are all in the correct and good working condition.