Tube Mills is a type of mill that have been around for a long time. While they may not be as popular as conveyor or roller milling machines today, there was a time when no other manufacturing process could produce such high-quality steel products with such economy. This type of production equipment was a huge leap forward in industries that require precision steel items, such as tube steel coils and tubes for pipes.
Tube Mills consists of rotating cylinders, usually the inside of which is almost completely plain. They have a large number of flat balls on their inside walls. They differ from roller mills in the lack of separate provision for the cooling of the welded arc, in which case a third cooling source is required. In addition, they tend to use more highly developed welding equipment, including high-tech laser welders. The tubes are sometimes also hand-woven in order to add even more precision to the finished product.
The most familiar tube mills are those that manufacture tubes for pipes. These are the size you usually find in building supplies stores and in plumbing supply warehouses. Typically, they feature a long cylindrical drum with a series of balls either side of it, which can spin at extremely high speeds, as well as providing the firmness necessary for drainage systems.
Tube mills work in a similar way to belt grinders, in that the user places the material (either wire or flat steel) into the drum, and “grinders” come into play. The “grinder” will move back and forth inside the cylinder, cutting either wire or flat steel to the desired diameter. Some will use a hand crank for this process, while others are operated by electric motor. Many use a variation of this same basic process: either grinding wire in from of the inside or grinding the entire thing out from the outside. This is done in order to obtain a consistent diameter and consistent profile, allowing for easy fitting and quick, clean up.
As for the actual grinding of ore, tube mills combine a pair of rotating discs (one with a ball inside) with a grinding wheel. The inside of the ball mill is filled with material (usually steel) that has been ground flat, before it is passed around the wheel and over the grinding surface. The balls inside the disc get “chipped off” as they pass, until there are only the edges left, which are used to make the cutting edge of the metal. This is also the method used in most belt grinders.
Another type of grinding operation often performed with tube mills is “idle side” production. Basically, anvils (or similar items) of different sizes are placed on either side of the blank, slowly being turned by a motor. As the anvils are turned, they force a piece of metal to rapidly form into a blank. When the blank is completely formed, it can then be quickly inserted into the grinding machine for maximum efficiency.