You Need a Hammer Mill for That…So, you have a material that you would like to make smaller for a given purpose. Sounds simple, right? Well, in most cases it is. However, there are a number of considerations that must be made to get you to the finish line in the most efficient and most economical way.
But First a Little BackgroundHammer mills are just one type of machinery among the much larger category of size reduction equipment that also includes: shredders, jaw crushers, ram fed grinders, roll mills, ball mills, and more. Looking a bit closer, even within hammer mills, there are several styles to choose from. Among those styles, the functionality of a hammer mill remains basically the same:
- Material is fed into a grinding chamber
- Contact with moving hammers, and interior mill components reduce the material’s size
- Material remains in the hammer mill’s grinding chamber until it is able to pass through a screen or grate with certain size openings.
Gravity Discharge Industrial Hammer Mills
Pneumatic Discharge Hammer MillsThe grinding mechanism of this group is quite simliar to the gravity discharge hammermills. However, the pneumatic mills typically use a thinner hammer and the interior wall of the grinding chamber features a ribbed liner plate. This plate has a washboard effect on the material, and works in unison with the hammers and particle on particle impact to reduce the material. The biggest difference of course is the group's the use of air assitance to evacuate material from the mill. Whether attached to the main mill shaft, or as a separate optional component in a high production model, the fan pulls the the material through the mill, and conveys it to storage.
Important to know: Specially designed notched hammers are ideal for tearing and shredding. In addition to assisting the evacuation of light or low density materials, the pneumatic suction can increase throughput up to 400% over gravity discharge hammer mills.
Ideal Applications: hogged wood scrap, wood chips, green wood, biomass, paper, carpet, meat and bone meal
Full Circle Screen Hammer MillsThis next group also features the same grinding mechanism as the first two, and the same thin hammers as the pneumatic hammer mills. The amount of screen coverage is what sets the full circle screen hammer mills apart.
Horizontal Infeed Hammer MillsThe unique quality of the horizontal infeed mills is that material is fed into the side of the hammer mill, instead of the top. This design makes them ideal for long, linear or otherwise large, geometric materials to be processed with out a pre-grind. This group includes trim scrap grinders and pallet grinders. As with the prior styles, the horizontal mills use heavy duty screens covering the discharge area to determine finished particle size.
Important to know: the style and design of the hammers aggressively moves the material into the mill. Feed rolls are ideal to properly control the rate that material enters the grinding chamber.
Ideal Applications: trim scrap, truss palnt scrap, 2x4s, whole pallets, pallet scrap