If you use a hammer mill, you feed the product to be processed inside the mill through an inlet box near the top and it is pre-crushed by a main beater tool upon reaching the top of the rotor. The beaters will also accelerate the product and moves it into the milling zone proper near the side of the rotor. There the grinding stock will be fluidized inside the air flow and will be comminuted by the rotor or stator or the grinding tools. The stator is formed by covering the enclosing rotor. Inside this cover is provided with toothed grooves that run vertically that is crosswise to the sense of rotation to the rotor. Outside the rotor, it is covered by various U-shaped sections which form some deep cassette-type of structure. This geometry then creates extreme air whirls inside the grinding zone of the rotor which induce intense secondary comminution stages because the particles are crashing into each other and also due to the shearing forces and friction. You can adjust the final particle size by adjusting over a wide range. This is done by changing the grinding rotor clearance, rotor speed and the air flow.
Aside from pulverization in the <100 um range, the hammer mill has truly proven to be very reliable as well as efficient when removing fibers from organic substances including cellulose, paper and paperboard. It is also very much reliable in cryogenic grinding, grinding or drying, grinding-coating and combined grinding and blending.
In the market, there are different grinding hammer mills being sold. As the buyer, you need to ascertain from whom you should buy and the kind of hammer mill that your company needs. When choosing the right hammer mill for your company, you can seek the assistance of experts or professionals who have ample experience in the industry. There are the so-called micro-grinding hammer mill systems which are typically designed to be efficient, fast and long lasting. You can also choose the freestanding 16 inches micro-grinding mill which is designed specifically for larger productions of processing ultra-fine pulverization of materials. The equipment can produce as fine as 200 mesh which would be dependent upon the material. The 11 inches bench unit is also out in the market and can produce some 100 mesh fineness during the first pass. Every mill has two outlets for the removal of ore. These outlets will allow you to run the ore dry or wet. For the 11 inches bench unit, the ore bin along with vacuum bag attached will collect the very dry ultra-fine powder as it exits by the top outlet down onto the hose. In running your material wet, you can make use of the bottom outlet or place a cap on the top outlet. Both mills are designed in order to create minimal dust leakage so that there will be an air control of the environment. During 2013, standard units usually come with carbide tipped hammers in order to promote greater wear ability.