While often simple in design, ball mills remain one of the most common and most useful methods of finely grinding and/or blending materials. Used for paint pigments, pyrotechnics, ceramics, mineral dressing processes, and more, ball mills help us create many of the products we rely on every single day. However, excessive heat generated by continuous ball mill usage can spell disaster for your processes and products. Below, we explain how overheating can impact your equipment’s performance and what preventive measures and products you can use to prevent overheating.
What is a Ball Mill?
A ball mill is a type of grinder commonly used for crushing or milling materials into an extremely fine form. A ball mill’s cylindrical shell is filled with large cylindrical pellets made of some material (typically stainless steel, or rubber). When the shell is rotated around its axis, the internal cascading effect of these balls and the material being ground within produces a fine powder.
Many industrial ball mills can operate continuously, and are used for grinding materials such as coal, pigments, pyrotechnics, and more. However, due to the internal friction created by this grinding process, excessive heat can be generated, decreasing the quality of the material inside.
Why Does Reducing Heat Matter?
How exactly does all that heat reduce the quality of your materials? Excessive heat can actually impact your production in several ways.
When it comes to the ball mill itself, extra heat can significantly reduce the output capabilities of your machine. The heat puts additional, unnecessary strain on the components of your machinery, decreasing the lifespan and endangering the safety of your equipment and potentially your employees.
Depending on the specific material you are working with, a hot ball mill can actually also impact your ability to store, pack, transport, and use these milled goods. For example, ball mills are often used for the creation of cement aggregate. If the ball mill making the cement is running hot, it can cause issues during construction, causing cracking and other product integrity hazards.
How To Prevent Abnormally High Temperatures in the Ball Mill Grinder
How can we prevent excessive amounts of heat from accumulating in the ball mill grinder? There are several ways of doing so, although some are preferred by industry professionals.
One potential method is strengthening the internal and external ventilation of the grinder. Heat taken away by ventilation systems can accounts for roughly 20% of the total heat discharged by the ball mill. Improving that ventilation system brings more cool air into the inside of the ball bill, gradually reducing the internal temperature.
However, the major benefit of using ball mills is the product fineness they can deliver. Therefore, the ventilation methods of many ball mill grinders are restricted by that fineness. Air vents must be no larger than the small material you are attempting to create.
Additional issues with proper ventilation are created by system resistance, air locks, and other air leaks. Accordingly, this method of ball mill cooling is often infeasible for many applications.
Typically, the most common and useful solution to overheating in the ball mill is to use a sprinkler system or other water injecting nozzles. Cool water introduced to the inside of the mill works to dissipate the accumulated heat, ensuring that the outlet temperature is kept at the desired level. So how do we get the water in the mill while still maintaining product quality?
Cooling Nozzle Solutions
A wide range of nozzle options exist to keep mills running at optimal temperatures. Usually, a single- or twin-fluid injection system is recommended and can be optionally fitted with rotary and feedthroughs for lances.
More About Nozzles & Lances
Ball mill cooling nozzles themselves have a low-maintenance design and can be quickly cleaned or exchanged with minimal effort. The lances also come with protective tubes used to increase the service life in case of higher temperatures, high dust loads, and aggressive gases.
Keep Your Equipment & Processes Cool With Lechler USA
Lechler cooling nozzles are designed to increase quality and efficiency across applications, including ball mill cooling. A wide range of specially developed and proven nozzles made from a variety of materials are available for gas conditioning – including the right ones for your own applications.
If you’d like more information on any of our nozzles for ball mill cooling or want to know more about how we can help you improve efficiencies across the board, contact us today and a member of our team will respond promptly.